In wireless networks, Quality of Service (QoS) is required to permit a wide range of users and applications to successfully share a limited resource, i.e. wireless spectrum. Conventional systems typically define QoS as a function of user, user class, group, group class, device, device class, application, application class, and/or stream type. When a network becomes congested, a scheduling function evaluates one or more of the above criteria and prioritizes one stream of data over another. Under some circumstances, such “one dimensional” prioritization rules may prove ineffective. For example, in circumstances where a large number of collocated users, all of the same class, are consuming the same media stream. Here, conventional scheduling functions and the “one dimensional” prioritization rules fall apart. Some conventional solutions exist where a system may arbitrarily “pick” one stream to favor over another, such that at least some of the streams are satisfied, while others are intentionally dropped or starved. While this at least provides serviceable streams to some individuals, the choice of individuals in a group is effectively random. Other conventional solutions exist where the bandwidth is shared fairly resulting in poor experiences for all users in these situations.
For example, consider a cluster of collocated public safety officers all sharing the same wireless resource (e.g., an evolved Node B (eNB) sector in a LTE system), such as may be found at an incident scene. Each officer is of the same rank, and each officer's radio is subscribed to a same audio talkgroup (e.g., is receiving the same outbound push-to-talk (PTT) audio stream). Under this scenario, a scheduler cannot use simple prioritization rules to determine which stream has priority, as all of the candidate streams are of the same priority (e.g., same user class, same user group, same stream type, same application, etc.). In another example, consider a multitude of sports fans attending the same football game. Each user is trying to receive a live video telecast of the game on their tablet devices, smart phones, etc. Because of the density of users connected to the same wireless resource (e.g., a WiFi access point, LTE eNB sector, etc.), insufficient bandwidth exists to deliver the video telecast to each user requesting access.
In scenarios where prioritization rules fail to differentiate streams to an extent where it is obvious which one to prioritize, a scheduler must fall back to ‘best effort’ or ‘fair’ scheduling techniques. Such maneuvers may be less than desirable across public safety, consumer applications, and other situations. In these instances, the behavior of the system becomes effectively non-deterministic and “best effort” in nature. In a group of collocated officers, for example, random devices may intermittently receive voice frames. In the aforementioned stadium example, random devices may intermittently receive video frames. In both cases, no single media stream to any one user is intact; moreover, no consideration is given to which users are receiving media.
Accordingly, there is a need for a spatial QoS prioritization algorithm in wireless networks.
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